J . Am. Chem. SOC.1994,116, 2223-2224
New Chiral Ruthenium Bis(oxazoliny1)pyridine Catalyst. Efficient Asymmetric Cyclopropanation of Olefins with Diazoacetates Hisao Nishiyama,' Yoshiki Itoh, Hideki Matsumoto, Soon-Bong Park, and Kenji Itoh
2223
Scheme 1
2
1
pybox-ip-(S,s)
School of Materials Science Toyohashi University of Technology Tempaku-cho, Toyohashi 441, Japan
in CHzC12 under Nz r.t , 10 min then CH2=CH2 (1 atm), l h
88 % yield
Received August 31, 1993 Cyclopropanation of olefins with diazoacetates has been one of the highlights of metal-catalyzed asymmetric synthesis in terms of both academic curiosities and industrial interests since Nozaki and co-workers initiated it about 30 years ago.' Its efficiency has recently been refined by chiral copper2and rhodium3 catalysts with new auxiliaries. We report herein an asymmetric cyclopropanation of olefins and diazoacetates with a powerful new chiral ruthenium catalyst in combination with bis(oxazoliny1)pyridine (pybox), which was developed by us as a chiral ligand for the rhodium-catalyzed hydr~silylation.~The catalytic activities of several ruthenium complexes for cyclopropanation with diazoacetates were reported in the early 1980s and proved to be nearly comparable to or less than those of copper and rhodium catalysts.5
We adopted [Ru"Cl2(p-cymene)]2 (1)6 as a readily available and stable precursor. Addition of a chiral ligand pybox-ip-(S,S) (2)4 to a solution of 1 in dichloromethane gave a dark red solution, which was stirred for 1 h at room temperature under ethylene atmosphere (1 atm) to give trans-C12Ru(pybox-ip)(CH2=CH2) (3) in 88% as a single product (Scheme l).' The C2-symmetrical structure of 3 was confirmed on the basis of its 'Hand 13C N M R spectra. Similar trans-C12Ru(pybox-ip)X complexes [X = CO and t-BuNC] were obtained by reaction with carbon monoxide (1)(a) Nozaki, H.; Moriuti, S.;Takaya, H.; Noyori, R. Tetrahedron Lett. (1 atm) and tert-butylisonitrile (1.2 equiv).* We thought that 1966,5239.(b) Nakamura, A.; Konishi, A.; Tatsuno, Y.; Otsuka, S.J. Am. Chem. Soc. 1978,100, 3443-3448,3449-3461. (c) Aratani, T. Pure Appl. the dark red solution might contain an unsaturated coordination Chem. 1985,57,1839-1844.For reviews: (d) Doyle, M. P. Chem. Rev. 1986, species Ru(pybox-ip)Clz or Ru(pybox-ip)Cl2(solv). We found 86,919-939. (e) Brookhart, M.; Studebaker, W. B. Chem. Rev. 1987,87, that the dark red solution and the ethylene complex 3 could 41 1-432.(f) Doyle, M. P. Red. Trau. Chim. Pays-Bas 1991,110,305-316. (g) Doyle, M. P. In Catalytic Asymmetric Synthesis; Ojima, I., Ed.; VCH: dimerize ethyl diazoacetate to produce a mixture of the correNew York, 1993;Chapter 3, pp 63-99. sponding maleate and the fumaratein high yields? In this respect, (2)Chiral copper catalysts. Semicorrin ligands: (a) Fritschi, H.; LeuCollman9a and Woo9b successfully isolated ruthenium- and tenegger, U.; Pfaltz, A. Angew. Chem., Int. Ed. Engl. 1986,25, 1005-1006. (b) Fritschi, H.; Leutenegger, U.; Pfaltz, A. Helu. Chim. Acta 1988, 71, osmium4arbene complexes of porphyrin derivatives by reaction 1553-1565.(c) Pfaltz, A. Ace. Chem. Res. 1993,26,339-345.Bis(oxazo1ine) with diazoacetates, respectively. However, we could not detect ligands: (d) Lowenthal, R. E.; Abiko, A.; Masamune, S.Tetrahedron k t t . the corresponding ruthenium-carbene complex by 1H N M R 1990,31,6005-6008.(e) Evans, D. A.; Woerpel, K. A.; Hinman, M. M.; Fad, study. M. M. J. Am. Chem. SOC.1991,113,726-728.(f) Miiller, D.; Umbricht, G.; Weber, B.; Pfaltz, A. Helu. Chim. Acta 1991, 74,232-240. For review: (9) Fortunately, we found that the dark red solution from 1 and Bolm, C. Angew. Chem., Int. Ed. Engl. 1991,30, 542-543. Other ligands: 2 (2-4 equiv) as an in situ catalyst (Ru, 2 mol % to diazoacetate, (h) Leutenegger, U.; Umbricht, G.; Fahrni, C.; Von Matt, P.; Pfaltz, A. ton = 50)(runs 1-5,Table 1) andalsothe Ru(pybox-ip)(ethylene) Tetrahedron 1992,48,2143-2156.(i) Brunner, H.; Wutz, K. New J. Chem. 1992,16,57-61. G) Ito, K.; Katsuki, T. Tetrahedron Lett. 1993,34,2661complex 3 (1-2 mol %) (runs 6-12) can catalyze the cyclopro2664.(k) Brunner, H.; Singh, U. P.; Boeck, T.; Altmann, S.;Scheck, T.; panation of diazoacetates (3.0 mmol) and styrene (15 mmol) to Wrackmeyer, B. J. Organomet. Chem. 1993,443,C16-Cl8. give the corresponding 2-phenylcyclopropanecarboxylates,the (3) Chiral rhodium catalysts: (a) Brunner, H.; Kluschanzoff, H.; Wutz, K. Bull. Chem. SOC.Belg. 1989,98,63-72.(b) Doyle, M. P.; Brandes, B. D.; trans-isomer 4, and the cis-isomer 5, in extremely high trans-cis Kazala, A. P.; Poeters, R. J.; Jarstfer, M. B.; Watkins, L. M.; Eagle, C. T. selectivity (9O:lO-98:2) and high enantioselectivity up to 96Tetrahedron Lett. 1990,31, 66136616.(c) Doyle, M. P.; Pieters, R. J.; 97%ee (1).10 The trans-cis ratio ( 4 / 5 ) increased with theincrease Martin, S.F.; Austin, R. E.; Oalmann, C. J.; Miiller, P. J. Am. Chem. SOC. 1991,123,1423-1424.(d) Maxwell,J.L.;OMalley,S.;Brown,K.C.;Kodadek, of bulkiness of the ester group (Me C Et C t-Bu z Ment; Ment T. Organometallics 1992, 11, 645452. (e) OMalley, S.;Kodadek, T. Organometallics 1992,11,2299-2302.For review: (f) Adams, J.; Spero, D. M. Tetrahedron 1991, 47, 1765-1808. (4)(a) Nishiyama,H.;Sakaguchi, H.;Nakamura,T.; Horihata, M.;Kondo, M.; Itoh, K. Organometallics 1989,8,846-848. (b) Nishiyama, H.; Kondo, M.; Nakamura, T.; Itoh, K. Organometallics 1991, 100, 500-508. (c) Nishiyama, H.; Park, S.-B.; Itoh, K. Tetrahedron: Asymmetry 1992,3,1029Yamaguchi, S.;Kondo, M.; Itoh, K. J. Org. Chem. 1034.(d) Nishiyama, H.; 1992,57,4306-4309. (e) Nagashima, H.; Ueda, T.; Nishiyama, H.; Itoh, K. Chem. Lett. 1993,347-350.(f) Nishiyama, H.; Yamaguchi, S.;Park, S.-B.; Itoh, K.Terrahedron: Asymmetry 1993,4,143-150.For review: (g) Brunner, H.; Nishiyama, H.; Itoh, K. In Catalytic Asymmetric Synthesis; Ojima, I., Ed.; VCH: New York, 1993;Chapter 6,pp 303-322. (5) (a) Anciaux, A. J.; Hubert, A. J.; Noels, A. F.; Petiniot, N.; Teyssib, P. J. Org. Chem. 1980,45,695-702.(b) Tamblyn, W. H.; Hoffmann, S.R.; Doyle, M. P. J. Organomet. Chem. 1981,216, C64C68.(c) Noels, A. F.; Demonceau, A.; Carlier, E.; Hubert, A. J.; Mbrquez-Silva, R.-L.; SBnchezDelgado, R. A. J. Chem.Soc., Chem. Commun.1988,783-784.(d) Bergbreiter, D. E.; Morvant, M.; Chen, B. Tetrahedron Lett. 1991,32, 2731-2734. (e) Demonceau, A.; Saive, E.; de Froidmont, Y.;Noels, A. F.; Hubert, A. J.; Chizhevskv. I. T.: Lobanova. I. A.: Bregadze. V. I. Tetrahedron Lett. 1992. 33, 2009-iO12. (f) Maas, 6.;Werle, T.;Ali, M.; Mayer, D. Tetrahedron 1993,49,881-888.
(6)Bennett, M. A.; Smith, A. K. J . Chem. SOC.,Dalton Trans. 1974, 233-241. (7)3 (88%, 0.29mmol) with I (0.16mmol) and 2 (0.33mmol): dark red solids; mp 103-104 OC dec; 'H NMR (270 MHz, CDClJ, TMS) 6 0.78 (d, J = 6.8 Hz, 6 H), 1.01 (d, J = 7.3 Hz, 6 H), 2.47 (m, 2 H), 4.43 (m, 2 H, NCH), 4.82(m, 2 H, H o f OCH), 4.89 (m, 2 H, H o f OCH), 4.94(m, 2 H, ethylene), 5.26 (m, 2 H, ethylene), 7.89 (broad, 3 H); '3C NMR (67.8MHz, CDC11, TMS) 6 14.30(q), 19.08 (q), 29.46(d), 70.46 (d), 71.00(t, OC-Hz), 71.68 (t, ethylene), 123.2 (d), 133.4 (d), 145.9 (s), 163.6 (s); EA CHN. (8) trans-ClzRu(pybox-ip)(CO), 92% yield. rrans-ClZRu(pybox-ip)(CNtBu), 81% yield. These complexes are air-stable and have no catalytic activity of dimerization and cyclopropanation below 40 'C. (9)High ratios of the maleate and the fumarate wereobserved: total yield, ratio (NzCHCOzR): for R = Et, 83%, 73:27;for R = i-Pr, 93%, 78:22;for R = t-Bu, 83%, 92% Similar cis-selectivity with Ru- and Os-porphyrins, see: (a) Collman, J. P.; Rose, E.; Venburg, G. D. J . Chem. SOC.,Chem. Commun. 1993,934-935.(b) Smith, D. A.; Reynolds, D. N.; Woo, L. K. J . Am. Chem. SOC.1993, 115, 2511-2513. (c) Woo, L. K.; Smith, D. A. Organometallics 1992,11, 2344-2346. (10) The cyclopropanation of styrene and ethyl diazoacetate with Cu(1)OTf(CsH&,s or Rh(II)*(OAc)d in the presence of pybox-ip (4 equiv) gave moderate yields of 4 and 5 (ca. 7:3)but low enantioselectivity (
